化工学报 ›› 2021, Vol. 72 ›› Issue (5): 2596-2603.DOI: 10.11949/0438-1157.20201429

• 催化、动力学与反应器 • 上一篇    下一篇

一种典型钒钛系SCR催化剂SO3生成特性研究

尹子骏1(),苏胜1(),卿梦霞2,赵志刚1,王中辉1,王乐乐3,江龙1,汪一1,胡松1,向军1   

  1. 1.华中科技大学煤燃烧国家重点实验室,湖北 武汉 430074
    2.长沙理工大学能源与动力工程学院,湖南 长沙 410114
    3.西安热工研究院有限公司苏州分公司,江苏 苏州 215153
  • 收稿日期:2020-10-12 修回日期:2020-11-26 出版日期:2021-05-05 发布日期:2021-05-05
  • 通讯作者: 苏胜
  • 作者简介:尹子骏(1996—),男,硕士研究生,291300330@qq.com
  • 基金资助:
    国家自然科学基金项目(51976072)

Study on SO3 formation characteristics of a typical vanadium titanium SCR catalyst

YIN Zijun1(),SU Sheng1(),QING Mengxia2,ZHAO Zhigang1,WANG Zhonghui1,WANG Lele3,JIANG Long1,WANG Yi1,HU Song1,XIANG Jun1   

  1. 1.State Key Laboratory of Coal Combustion, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China
    2.School of Energy and Power Engineering, Changsha University of Science & Technology, Changsha 410114, Hunan, China
    3.Xi’an Thermal Power Research Institute Company Limited, Suzhou Branch, Suzhou 215153, Jiangsu, China
  • Received:2020-10-12 Revised:2020-11-26 Online:2021-05-05 Published:2021-05-05
  • Contact: SU Sheng

摘要:

选择性催化还原(SCR)技术由于脱硝效率高、选择性好而被广泛应用于烟气氮氧化物排放控制;然而,目前广泛采用的钒钛系SCR脱硝催化剂会使烟气中SO2氧化成SO3,烟气中过高的SO3对电厂安全运行会造成严重影响,也会对环境造成污染。以典型V2O5-WO3/TiO2催化剂为研究对象,系统研究了SCR脱硝过程中烟气流量、温度、O2浓度、SO2浓度等对催化剂表面SO3生成特性的影响,并进一步对SO3生成的反应动力学特性进行了分析。研究表明:催化剂表面SO3生成反应中SO2的反应级数为0.59,当O2浓度大于3%时,O2的反应级数为0,该反应的表观活化能为70.39 kJ/mol;实验条件下,烟气中SO2浓度增加会使SO3生成的反应速率提高;O2浓度对催化剂表面SO3生成影响并不显著;烟气温度对催化剂表面SO3生成具有显著影响,高温会促进SO3的生成。

关键词: SCR催化剂, 燃煤烟气, SO2, SO3, 反应动力学

Abstract:

Selective catalytic reduction (SCR) technology is widely used in flue gas nitrogen oxide emission control due to its high denitration efficiency and good selectivity; however, currently widely used vanadium titanium SCR catalyst can oxidize SO2 in flue gas into SO3, and excessive SO3 in flue gas will cause serious impact on the safe operation of power plant and also cause environmental pollution. Taking commercial V2O5-WO3/TiO2 catalyst as the research object, the effects of flue gas flowrate, temperature, O2 concentration and SO2 concentration on the formation of SO3 on the catalyst during SCR denitrification were systematically studied, and the reaction kinetics of SO3 formation was further discussed. The results show that the reaction order of SO2 is 0.59. When the concentration of O2 is more than 3%, the reaction order of O2 is 0, and the activation energy of SO3 formation on catalyst is 70.39 kJ/mol. The increase of SO2 concentration will increase the reaction rate of SO3 formation; O2 concentration has no significant effect on the formation of SO3 on the catalyst. The temperature of flue gas has a significant effect on the formation of SO3, and high temperature can promote the formation of SO3.

Key words: SCR catalyst, coal fired flue gas, SO2, SO3, reaction kinetics

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